Looping Over Specific Symbols Of All Exchanges

import ccxt from '../../js/ccxt.js';
import asTable from 'as-table';
import ololog from 'ololog';
import ansicolor from 'ansicolor';

const log       = ololog.configure ({ locate: false }), verbose   = process.argv.includes ('--verbose');

ansicolor.nice

//-----------------------------------------------------------------------------

;(async () => {

   const exchanges = {};
   const symbols = [ 'ETH/BTC', 'XRP/BTC', 'BTC/USDT' ]

   for (let symbol of symbols) {

       for (let exchangeId of ccxt.exchanges) {

           let exchange = undefined

           try { // try creating the exchange instance first and handle errors if any

               // check if we have created an instance of this exchange already

               exchange = exchanges[exchangeId]

               if (exchange === undefined) {

                   // create the exchange instance
                   exchange = new ccxt[exchangeId] ()
               }

               exchanges[exchangeId] = exchange // save it for later use

           } catch (e) {

               log.red ('Could not create exchange', exchangeId + ':', e.constructor.name, e.message)

               // uncomment the following line to interrupt program execution on error
               // or leave it commented out to do nothing

               // process.exit ()

           }

           if (exchange !== undefined) {

               // preload all markets first, as explained in the Manual:
               // https://github.com/ccxt/ccxt/wiki/Manual#loading-markets

               // add error/exception handling as required by the Manual:
               // https://github.com/ccxt/ccxt/wiki/Manual#error-handling

               try {

                   await exchange.loadMarkets ();

               } catch (e) {

                   log.red ('Could not load markets from', exchange.id + ':', e.constructor.name, e.message)
                   continue; // skip this exchange if markets failed to load

               }

               for (let symbol of symbols) {

                   console.log (exchange.id, symbol)

                   // add error/exception handling as required by the Manual:
                   // https://github.com/ccxt/ccxt/wiki/Manual#error-handling

                   try { // try fetching the ticker for a symbol existing with that exchange

                       const ticker = await exchange.fetchTicker (symbol)
                       log.green (ticker)

                   } catch (e) { // catch the error (if any) and handle it or ignore it

                       log.red ('Could not fetch', symbol, 'ticker from', exchange.id + ':', e.constructor.name, e.message)

                   }
               }
           }
       }
   }

}) ()